A Simple Fix for Farming

IT’S becoming clear that we can grow all the food we need, and profitably, with far fewer chemicals. And I’m not talking about imposing some utopian vision of small organic farms on the world. Conventional agriculture can shed much of its chemical use — if it wants to.

This was hammered home once again in what may be the most important agricultural study this year, although it has been largely ignored by the media, two of the leading science journals and even one of the study’s sponsors, the often hapless Department of Agriculture.

The study was done on land owned by Iowa State University called the Marsden Farm. On 22 acres of it, beginning in 2003, researchers set up three plots: one replicated the typical Midwestern cycle of planting corn one year and then soybeans the next, along with its routine mix of chemicals. On another, they planted a three-year cycle that included oats; the third plot added a four-year cycle and alfalfa. The longer rotations also integrated the raising of livestock, whose manure was used as fertilizer.

The results were stunning: The longer rotations produced better yields of both corn and soy, reduced the need for nitrogen fertilizer and herbicides by up to 88 percent, reduced the amounts of toxins in groundwater 200-fold and didn’t reduce profits by a single cent.

In short, there was only upside — and no downside at all — associated with the longer rotations. There was an increase in labor costs, but remember that profits were stable. So this is a matter of paying people for their knowledge and smart work instead of paying chemical companies for poisons. And it’s a high-stakes game; according to the Environmental Protection Agency, about five billion pounds of pesticidesare used each year in the United States.

No one expects Iowacorn and soybean farmers to turn this thing around tomorrow, but one might at least hope that the U.S.D.A.would trumpet the outcome. The agency declined to comment when I asked about it. One can guess that perhaps no one at the higher levels even knows about it, or that they’re afraid to tell Monsantoabout agency-supported research that demonstrates a decreased need for chemicals. (A conspiracy theorist might note that the journals Science and Proceedings of the National Academy of Sciences both turned down the study. It was finally published in PLOS One; I first read about it on the Union of Concerned Scientists Web site.)